[unittests] Fix OptionSet->intptr_t test for older Clang versions.
[unittests] Fix OptionSet->intptr_t test for older Clang versions.

clang-600 doesn't consider explicit conversion operators as satisfying
std::is_constructible, even though actually writing the construction
does work. Just don't run that part of the test if that's how
std::is_constructible behaves.

Swift SVN r24603

kusl/swift,harlanhaskins/swift,brentdax/swift,natecook1000/swift,OscarSwanros/swift,adrfer/swift,lorentey/swift,kentya6/swift,ken0nek/swift,sdulal/swift,harlanhaskins/swift,devincoughlin/swift,ben-ng/swift,djwbrown/swift,johnno1962d/swift,felix91gr/swift,gregomni/swift,hooman/swift,uasys/swift,Ivacker/swift,allevato/swift,Jnosh/swift,stephentyrone/swift,zisko/swift,swiftix/swift.old,manavgabhawala/swift,atrick/swift,khizkhiz/swift,gribozavr/swift,brentdax/swift,mightydeveloper/swift,JaSpa/swift,atrick/swift,kentya6/swift,manavgabhawala/swift,airspeedswift/swift,zisko/swift,tardieu/swift,ken0nek/swift,austinzheng/swift,IngmarStein/swift,emilstahl/swift,arvedviehweger/swift,glessard/swift,nathawes/swift,danielmartin/swift,swiftix/swift,ken0nek/swift,dduan/swift,modocache/swift,practicalswift/swift,gribozavr/swift,sschiau/swift,gmilos/swift,xedin/swift,KrishMunot/swift,tinysun212/swift-windows,IngmarStein/swift,milseman/swift,amraboelela/swift,sdulal/swift,xedin/swift,OscarSwanros/swift,alblue/swift,jopamer/swift,aschwaighofer/swift,shajrawi/swift,gottesmm/swift,apple/swift,therealbnut/swift,russbishop/swift,kentya6/swift,shahmishal/swift,xedin/swift,danielmartin/swift,felix91gr/swift,xwu/swift,MukeshKumarS/Swift,slavapestov/swift,apple/swift,gmilos/swift,swiftix/swift.old,modocache/swift,dreamsxin/swift,therealbnut/swift,manavgabhawala/swift,slavapestov/swift,karwa/swift,codestergit/swift,KrishMunot/swift,airspeedswift/swift,gottesmm/swift,gmilos/swift,emilstahl/swift,devincoughlin/swift,lorentey/swift,calebd/swift,stephentyrone/swift,tjw/swift,tjw/swift,nathawes/swift,karwa/swift,jtbandes/swift,huonw/swift,tkremenek/swift,arvedviehweger/swift,IngmarStein/swift,harlanhaskins/swift,djwbrown/swift,jckarter/swift,apple/swift,emilstahl/swift,manavgabhawala/swift,calebd/swift,shajrawi/swift,JGiola/swift,atrick/swift,allevato/swift,cbrentharris/swift,jtbandes/swift,calebd/swift,jtbandes/swift,airspeedswift/swift,hughbe/swift,jopamer/swift,amraboelela/swift,arvedviehweger/swift,tinysun212/swift-windows,dduan/swift,arvedviehweger/swift,return/swift,adrfer/swift,sschiau/swift,frootloops/swift,zisko/swift,rudkx/swift,kentya6/swift,tinysun212/swift-windows,IngmarStein/swift,zisko/swift,tjw/swift,rudkx/swift,LeoShimonaka/swift,emilstahl/swift,djwbrown/swift,parkera/swift,sschiau/swift,kperryua/swift,allevato/swift,tjw/swift,slavapestov/swift,shajrawi/swift,gribozavr/swift,Ivacker/swift,bitjammer/swift,MukeshKumarS/Swift,sschiau/swift,rudkx/swift,manavgabhawala/swift,KrishMunot/swift,JaSpa/swift,khizkhiz/swift,jckarter/swift,parkera/swift,SwiftAndroid/swift,ahoppen/swift,mightydeveloper/swift,atrick/swift,JGiola/swift,swiftix/swift.old,ben-ng/swift,khizkhiz/swift,SwiftAndroid/swift,arvedviehweger/swift,johnno1962d/swift,parkera/swift,slavapestov/swift,MukeshKumarS/Swift,kentya6/swift,LeoShimonaka/swift,tkremenek/swift,LeoShimonaka/swift,parkera/swift,frootloops/swift,tardieu/swift,benlangmuir/swift,swiftix/swift,apple/swift,jckarter/swift,slavapestov/swift,lorentey/swift,austinzheng/swift,uasys/swift,gribozavr/swift,lorentey/swift,alblue/swift,russbishop/swift,brentdax/swift,austinzheng/swift,kusl/swift,shajrawi/swift,Jnosh/swift,felix91gr/swift,practicalswift/swift,LeoShimonaka/swift,cbrentharris/swift,lorentey/swift,hughbe/swift,Jnosh/swift,roambotics/swift,calebd/swift,sdulal/swift,natecook1000/swift,alblue/swift,sdulal/swift,return/swift,tardieu/swift,return/swift,Ivacker/swift,jmgc/swift,return/swift,harlanhaskins/swift,kstaring/swift,huonw/swift,kperryua/swift,bitjammer/swift,kentya6/swift,lorentey/swift,nathawes/swift,tkremenek/swift,dduan/swift,xedin/swift,shahmishal/swift,roambotics/swift,deyton/swift,milseman/swift,devincoughlin/swift,karwa/swift,LeoShimonaka/swift,LeoShimonaka/swift,xedin/swift,swiftix/swift,khizkhiz/swift,MukeshKumarS/Swift,huonw/swift,gribozavr/swift,gregomni/swift,arvedviehweger/swift,Jnosh/swift,xedin/swift,ahoppen/swift,LeoShimonaka/swift,shajrawi/swift,tardieu/swift,russbishop/swift,cbrentharris/swift,kstaring/swift,brentdax/swift,cbrentharris/swift,ken0nek/swift,shajrawi/swift,shahmishal/swift,aschwaighofer/swift,swiftix/swift,felix91gr/swift,swiftix/swift.old,OscarSwanros/swift,bitjammer/swift,kentya6/swift,roambotics/swift,kstaring/swift,tkremenek/swift,manavgabhawala/swift,deyton/swift,djwbrown/swift,austinzheng/swift,airspeedswift/swift,kstaring/swift,kusl/swift,shahmishal/swift,kperryua/swift,uasys/swift,MukeshKumarS/Swift,shajrawi/swift,sdulal/swift,uasys/swift,KrishMunot/swift,Jnosh/swift,ben-ng/swift,ken0nek/swift,airspeedswift/swift,gregomni/swift,kperryua/swift,sdulal/swift,dduan/swift,nathawes/swift,milseman/swift,aschwaighofer/swift,JaSpa/swift,SwiftAndroid/swift,tinysun212/swift-windows,practicalswift/swift,harlanhaskins/swift,xwu/swift,kperryua/swift,johnno1962d/swift,danielmartin/swift,devincoughlin/swift,swiftix/swift.old,khizkhiz/swift,natecook1000/swift,SwiftAndroid/swift,emilstahl/swift,stephentyrone/swift,gmilos/swift,atrick/swift,huonw/swift,hooman/swift,kperryua/swift,frootloops/swift,johnno1962d/swift,djwbrown/swift,bitjammer/swift,ahoppen/swift,OscarSwanros/swift,glessard/swift,natecook1000/swift,djwbrown/swift,stephentyrone/swift,benlangmuir/swift,CodaFi/swift,karwa/swift,modocache/swift,devincoughlin/swift,jopamer/swift,zisko/swift,felix91gr/swift,ben-ng/swift,rudkx/swift,natecook1000/swift,glessard/swift,gottesmm/swift,IngmarStein/swift,hughbe/swift,JaSpa/swift,devincoughlin/swift,dreamsxin/swift,gmilos/swift,Jnosh/swift,austinzheng/swift,xwu/swift,roambotics/swift,tkremenek/swift,karwa/swift,kperryua/swift,nathawes/swift,alblue/swift,djwbrown/swift,adrfer/swift,alblue/swift,CodaFi/swift,jckarter/swift,kstaring/swift,modocache/swift,roambotics/swift,airspeedswift/swift,tjw/swift,tkremenek/swift,milseman/swift,aschwaighofer/swift,danielmartin/swift,jopamer/swift,danielmartin/swift,hughbe/swift,benlangmuir/swift,kstaring/swift,emilstahl/swift,amraboelela/swift,aschwaighofer/swift,russbishop/swift,austinzheng/swift,hooman/swift,deyton/swift,jtbandes/swift,CodaFi/swift,Ivacker/swift,gottesmm/swift,frootloops/swift,johnno1962d/swift,amraboelela/swift,shahmishal/swift,gregomni/swift,kusl/swift,sschiau/swift,slavapestov/swift,roambotics/swift,huonw/swift,hughbe/swift,JaSpa/swift,milseman/swift,gribozavr/swift,calebd/swift,allevato/swift,shahmishal/swift,russbishop/swift,johnno1962d/swift,aschwaighofer/swift,frootloops/swift,karwa/swift,hooman/swift,jckarter/swift,natecook1000/swift,sdulal/swift,karwa/swift,sschiau/swift,milseman/swift,tinysun212/swift-windows,codestergit/swift,shahmishal/swift,jmgc/swift,kusl/swift,codestergit/swift,therealbnut/swift,emilstahl/swift,apple/swift,jopamer/swift,parkera/swift,huonw/swift,sdulal/swift,Ivacker/swift,khizkhiz/swift,rudkx/swift,emilstahl/swift,mightydeveloper/swift,glessard/swift,kentya6/swift,harlanhaskins/swift,rudkx/swift,tinysun212/swift-windows,CodaFi/swift,hooman/swift,practicalswift/swift,gmilos/swift,ahoppen/swift,return/swift,IngmarStein/swift,jmgc/swift,gregomni/swift,uasys/swift,LeoShimonaka/swift,devincoughlin/swift,slavapestov/swift,amraboelela/swift,practicalswift/swift,gottesmm/swift,jtbandes/swift,MukeshKumarS/Swift,JaSpa/swift,swiftix/swift.old,felix91gr/swift,stephentyrone/swift,return/swift,adrfer/swift,mightydeveloper/swift,JGiola/swift,OscarSwanros/swift,mightydeveloper/swift,modocache/swift,deyton/swift,MukeshKumarS/Swift,ken0nek/swift,mightydeveloper/swift,danielmartin/swift,codestergit/swift,alblue/swift,codestergit/swift,dduan/swift,mightydeveloper/swift,tardieu/swift,return/swift,atrick/swift,xwu/swift,jtbandes/swift,sschiau/swift,jtbandes/swift,JGiola/swift,adrfer/swift,lorentey/swift,cbrentharris/swift,Ivacker/swift,khizkhiz/swift,tkremenek/swift,swiftix/swift,hooman/swift,codestergit/swift,JGiola/swift,xwu/swift,xwu/swift,tardieu/swift,ben-ng/swift,therealbnut/swift,parkera/swift,zisko/swift,deyton/swift,SwiftAndroid/swift,sschiau/swift,ben-ng/swift,mightydeveloper/swift,ben-ng/swift,devincoughlin/swift,jmgc/swift,ahoppen/swift,calebd/swift,airspeedswift/swift,nathawes/swift,jmgc/swift,alblue/swift,dduan/swift,zisko/swift,xedin/swift,cbrentharris/swift,OscarSwanros/swift,modocache/swift,calebd/swift,shahmishal/swift,ken0nek/swift,jckarter/swift,milseman/swift,swiftix/swift,felix91gr/swift,dduan/swift,tjw/swift,jmgc/swift,huonw/swift,hughbe/swift,Ivacker/swift,bitjammer/swift,lorentey/swift,gottesmm/swift,uasys/swift,OscarSwanros/swift,practicalswift/swift,amraboelela/swift,swiftix/swift.old,amraboelela/swift,manavgabhawala/swift,nathawes/swift,natecook1000/swift,frootloops/swift,CodaFi/swift,benlangmuir/swift,IngmarStein/swift,austinzheng/swift,CodaFi/swift,arvedviehweger/swift,adrfer/swift,deyton/swift,therealbnut/swift,hughbe/swift,stephentyrone/swift,Ivacker/swift,cbrentharris/swift,kusl/swift,modocache/swift,gmilos/swift,xedin/swift,jmgc/swift,johnno1962d/swift,kstaring/swift,practicalswift/swift,cbrentharris/swift,jopamer/swift,brentdax/swift,glessard/swift,brentdax/swift,swiftix/swift.old,jopamer/swift,KrishMunot/swift,JaSpa/swift,brentdax/swift,allevato/swift,allevato/swift,aschwaighofer/swift,gribozavr/swift,parkera/swift,russbishop/swift,adrfer/swift,kusl/swift,tjw/swift,kusl/swift,practicalswift/swift,benlangmuir/swift,codestergit/swift,uasys/swift,SwiftAndroid/swift,gregomni/swift,Jnosh/swift,bitjammer/swift,swiftix/swift,russbishop/swift,jckarter/swift,ahoppen/swift,therealbnut/swift,gottesmm/swift,JGiola/swift,KrishMunot/swift,frootloops/swift,SwiftAndroid/swift,danielmartin/swift,xwu/swift,stephentyrone/swift,CodaFi/swift,parkera/swift,karwa/swift,hooman/swift,apple/swift,KrishMunot/swift,glessard/swift,tardieu/swift,tinysun212/swift-windows,bitjammer/swift,gribozavr/swift,benlangmuir/swift,shajrawi/swift,therealbnut/swift,deyton/swift,harlanhaskins/swift,allevato/swift